ELENA / AD Pick-ups and Schottky Wolfgang Hofle, 7 March 2019

ELENA longitudinal pick-ups (LPU) Principle follows the design by F. Pedersen for AD Low frequency version: 3 kHz - 3 MHz High Frequency version: 800 kHz - 30 MHz different types of ferrites are used for the two versions Wolfgang Hofle, 7 March 2019

ELENA longitudinal pick-up assembly Design: J. Sanchez Quesada, F. Pedersen, F. Caspers, S. Federmann et al. http://accelconf.web.cern.ch/AccelConf/IBIC2013/papers/tupf27.pdf Mechanical engineering with Central Workshop Amplifier design and commissioning in BE-RF-FB R. Louwerse assigned for its performance improvement after Departure of J. Sanchez Quesada Help from F. Caspers available Wolfgang Hofle, 7 March 2019

Status of ELENA LPUs Four pick-ups were planned within the project 3 low frequency pick-ups (LF) 1 high frequency pick-up (HF) The HF and LF Schottky LPU are installed in the ELENA ring The signals they provide suffer from interference this is being looked at with priority Combining the signals correctly for different energies requires an adjustable delay between the two (depending on beam energy) that needs completion (electronics) The remote control of the gain requires completion of work in BE-RF-CS The LF pick-up in the extraction line to Gbar (LNE50) was installed in 2018 and has measured the intensity of the extracted bunches through a system of digitization and calibration provided by BI (J.C. Allica Santamaria) Signals are also available on OASIS (since 2018) Cabling is prepared for the last of the four pick-ups, a LF version for the LNE00 line Nota bene: LNE50 LPU has small leak (?); no spare pick-up Wolfgang Hofle, 7 March 2019

Head amplifier powered remotely from the rack powering through a long cable with feedback to stabilize DC voltage interference observed and oscillatory behaviour of voltage regulation mitigation in ELENA ring by local power supply (mid June 2018); reducing regulation bandwidth on electronics implemented during 2nd half of 2018 (R. Louwerse) Wolfgang Hofle, 7 March 2019

Test in June 2018 (LF version in LNE50) Wolfgang Hofle, 7 March 2019

Powering locally from lab supply Powered from rack with operationally used supply Powered locally from a lab supply in the ring LF LPU LNE50 LF LPU LNE50 400 mVpp 20 mVpp LF LPU Ring LF LPU Ring 80 mVpp 20 mVpp Signals without beam, output of pe-amplifier

Ring PUs with local powering Frequency response to be adjusted Delay for combined signal to be checked 27.06.2019 (pbar) D. Gamba Wolfgang Hofle, 7 March 2019

LF LPU for LNE00 and strategy Pick-up mechanically completed Leak tested and accepted by TE-VSC after bake-out Test stand being prepared for the electrical tests with pre-amplifier in building 112 Wolfgang Hofle, 7 March 2019

Completion of electronics and installation Mitigation of noise and interference through testing in 112 and trying out modifications Test of operational set of electronics in 112 for LNE00 Test of spare set of electronics in 112 with pick-up Installation in LNE00 of pick-up and electronics Repeat measurements to see if situation in ELENA is different from the lab environment Decision on needed modifications of the electronics and on spare electronics depending on the outcome of the tests (budget from operations, ~10 kCHF may be needed) Wolfgang Hofle, 7 March 2019